I鈥檝e just read that eggs should not be stored in a rack on the back of a fridge door, the exact place where most fridge manufacturers put the egg rack. Before I revamp my fridge, is there any truth to this? And if so, what could it be?
鈥� Once an unfertilised egg drops out of the back of a chicken, it crosses the road towards decay. This is because chick embryos need to breathe, so eggs must be gas-permeable. Even in the absence of an embryo, carbon dioxide diffuses out through the shell, and this makes the interior less acidic. Water from the white, or albumen, also diffuses outwards and, by osmosis, into the yolk.
The egg white thus becomes inhospitable to healthy proteins, which have a naturally folded structure that depends on the local acidity. This in turn swells the yolk and makes membrane more fragile. If you ever try to make a souffl茅 using old eggs, you will find that the whites and yolks have become inseparable.
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鈥淒id fridge-makers put egg racks inside fridge doors because they did not know how else to use the space?鈥�
All these processes speed up with temperature, so storing eggs in the fridge is a good start. But an open rack behind the door is not the best spot. When you open the fridge, you waft fresh, warm air over any layer of carbon dioxide that has built up at the egg鈥檚 surface. This encourages yet more diffusion out of the egg, and thus yet more ageing. You also tend to shake the eggs, resulting in a more watery albumen by mixing the thick and thin components of the white.
The best place in the fridge to store eggs is probably in a sealed box, to prevent diffusion, and as low down as possible 鈥� in other words, in the coolest part. This slows the loss of carbon dioxide and water to the air, and also prevents the egg taking up odours from inside the fridge.
It is worth remembering that eggs emerge from a contaminated part of a bird鈥檚 anatomy, so routinely harbour bacteria, notably Salmonella enteritidis. A sealed box would stop egg-winds wafting over the other contents of your fridge. We should also clean the egg rack regularly, wherever in the fridge it may be.
I wonder if fridge-makers originally put egg racks inside the doors because they could not think what else to use these tiny spaces for.
Simon Goodman, Griesheim, Germany
鈥� Eggs can be stored in the fridge, preferably in a box to slow water loss, but they should be taken out and allowed to reach room temperature before cooking. This is important if you like a soft yolk: oeufs en cocotte and eggs sunny side up don鈥檛 work otherwise, because when the white is cooked, the yolk is still only lukewarm. I learned this back in the 60s when working as a short-order chef at a motorway services, where I also learned to crack eggs single-handed.
Luce Gilmore, Cambridge, UK
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